Prevalence of Reading Difficulties: 4th-8th Grade The central goal of this project is to estimate the prevalence of various types of reading disability (RD) in the population of upper elementary and middle school students (grades 4 and 8). We will conduct a two-stage probability sampling of public schools throughout the state of New Jersey, and will assess reading and related skills in that sample. The schools in the sampling frame will be stratified by enrollment size (large, medium, and small) and by the socioeconomic and ethnic composition of the community served by the school. Prevalence estimates will be derived for overall RD and separately for each subtype of RD that is identified in Projects 1,11, and III of the LDRC as being distinct from other types in its occurrence and its patterns of association with cognitive-linguistic skills. It is anticipated that these RD profiles of interest will include deficits, alone and in combination, in comprehending text, recognizing/decoding words, and reading fluency. We will also examine the relative prevalence of each RD subtype according to demographic factors (age/grade, gender, socioeconomic status, ethnicity) and other student characteristics, especially ADHD and English language proficiency. By collecting data about family, community, school, and instructional contexts, we will be able to investigate relationships between disadvantage/poverty and RD, and to identify potential risk and protective factors within these contexts. Determining the prevalence and distribution of reading difficulties across this age range and within subgroups of the population is of critical importance for designing reading instruction and school services that can best address the needs of struggling readers beyond the primary grades. Findings from this prevalence study will be able to be extrapolated to the nation, which will help guide educators in terms of the which instructional emphases are needed for older readers, as well as how to best identify struggling readers.